I talked to current and former Google employees, along with others who have worked with Hugo Barra, to assess what the company has lost now that he is departing for Xiaomi — and how Android will proceed without him.

To those outside the division, Barra was a rare friendly face at Android. He had a quick smile and an easy way with outsiders, and he had mastered that most crucial of the corporate arts: the presentation. "He was the go-to guy if you wanted to have a kickass demo," a colleague from another division said. "Especially if you wanted a demo of something Android, because you could never get Andy Rubin to do anything."